For any group of people that put a value on free speech, a powerful tool for progress, it will always be the things we don't want to hear and things that make us upset that need the most protection. Discouraging people from talking about how they feel, and going so far as to ensure what they have to say does nothing to eliminate the ideas and feelings that people have.
It is not a bad thing to imagine a world where everyone loves each other and can get along in peace, but hate speech is a symptom than a cause of a real problem. In medicine, a sick person can be running a fever, but putting them in cold water does not heal the sickness.
Some people will always find excuses to be violent, no matter how quickly the excuse of the day can be censored. If what you want is to discourage violence, property damage, and fear, educate people on the principle and value of the free expression of ideas. Free people from the fear of expressing their opinion, and free people from fear of the opinions of others that they may disagree with, albeit strongly.
This mutual respect for will be a necessary tool for peace. Let people know what is really intolerable and come down hard. Creating a gray area for non-violent hate mongers is corrosive to law and the civil society, and too often what can be considered 'hate speech' yesterday, today, or tomorrow changes with the political atmosphere.
I am not denying that there are real problems in Kenya, just saying that a cautious (not to imply slow), structured, pragmatic approach will be necessary to make real change.
1. Educate for speech tolerance and against violence.
2. As much as necessary, swat / riot teams PROTECT protesters / non-violent expressions of all people equally.
3. Quickly and aggressively (zip ties are good for this) break up physical confrontations and acts of violence.
Targeting the problem as directly and narrowly as possible prevents resources from being spread thin, and builds public confidence of governmental objectivity.
Please, do not make 'hate' the gray area of violence any more than you desire violence be the gray area of free expression.